1. Field of the Invention
The present invention concerns a stapler comprising an elongate loader adapted to receive sticks of staples with a back width in a particular range of widths and a loader cover attached to a rail and mobile between a first position in which it allows access to the loader and a second position in which the rail passes between the legs of a stick of staples installed in the loader to guide them towards a driver that can be operated to separate the staple at the head of the stick and implant it in a final support.
2. Description of the Prior Art
Staplers of the above kind designed to receive different size staples are known in themselves, for example the ROCAFIX MS 10 stapler supplied by the French company Sofragraf Industries. The instructions for installing a straight stick of staples in the loader of the stapler specify that said stick must bear against a particular lateral flank of the loader before the cover is moved from its first position to its second position in which the rail passes between the legs of the staples in the stick. If a stick of staples with a xe2x80x9cbackxe2x80x9d width (leg spacing) less than the maximal width accepted by the stapler bears on the other flank of the loader and the cover carrying the staple guide rail is then moved towards its second position in which it closes the loader, the rail can butt up against the stick of staples in the loader instead of passing freely between the legs of the staples. It is then impossible to close the loader and use the stapler.
FR-A-2 568 813 describes another stapler designed to accept different size staples. It includes an elongate magazine (loader) comprising two U-sections joined by a central support member serving as a rail for the staples. The two sections have different widths. One is narrow to closely surround one branch (leg) of a staple. The other is wider so that it can accommodate the other leg of the staple regardless of its back width provided that this width is within a predetermined range of widths. Installing a stick of staples on a rail of the above kind calls for some care because a part of the stick must be inserted into a narrow U-section the width of which is only slightly greater than the thickness of the wire from which the thickest staples that the stapler can receive are made.
An aim of the present invention is to provide a stapler of the type described in the preamble to this description that does not have any of the disadvantages mentioned above and which therefore enables the fitting without special precautions of a stack or stick of staples whose back width can vary within a predetermined range.
The above aim of the invention, and others that will become apparent after reading the following description, are achieved with a stapler of the type described in the preamble to this description that is remarkable in that the rail is positioned on the loader cover and has transverse dimensions such that when it is moved to its second position it can pass freely between the legs of the staples of a stick of staples having a back width at least equal to a lower threshold of the range of predetermined widths, whether the staples bear against one or the other of two parallel lateral flanks of the loader and cam means are provided to move the rail laterally when the cover moves from its first position to its second position.
As will become apparent later, this lateral movement assures close guidance of the stick of staples in the loader regardless of the back width of the staples in the stick provided that this width is within the predetermined range of widths.